Short-seller Carson Block discussed GameStop, SPACs, and Archegos in a recent interview. Here are the 10 best quotes.

• Carson Block doubts retail investors can execute another GameStop-level short squeeze.
• The Muddy Waters boss warned that many recent SPACs are worth nothing.
• Here are Block's 10 best quotes from a recent interview.
• See more stories on Insider's business page.

Short-seller Carson Block argued in a recent RealVision interview that retail investors would struggle to pull off another GameStop-style short squeeze, dismissed many recent SPACs are worthless, and suggested Archegos Capital was managing a $150 billion-plus portfolio before it blew up.

The Muddy Waters boss also defended short-sellers, warned that many investors won't be sufficiently hedged when the market crashes, and cheered day traders for making it easier to establish short positions.

Here are Block's 10 best quotes from the interview, lightly edited and condensed for clarity:

1. "We suspect Archegos' trading book had originally been $150 billion to $200 billion. We think there's still a decent amount of positions to work through." - Block's estimate is several times bigger than has been reported.

2. "GameStop was a democratization of this tactic of creating squeezes."

3. "When playing squeezes becomes a real strategy that's happening on a widespread basis, it's just another symptom that the markets are not healthy. They're not performing their intended functions of allocating capital efficiently in the economy to the best users of capital. That's my view on GameStop."

4. "I don't know if retail could pull the same trick again on GameStop and these other meme stocks. They were able to do this in broad daylight, as the guys who were short weren't looking and weren't aware. Now there's much more of an appreciation for the risk that's inherent in being in a heavily shorted name. I'm going to assume that almost every smart-money hedge fund is just looking at Reddit constantly and would have indications of a squeeze coming."

5. "Every time I tweet, I get a bunch of people tweeting back, 'Let's squeeze him, squeeze is coming.' I'm like, 'Thanks for letting me know, bro.'"

6. "You've got the companies that are really deserving of being shorted, and then you've got the companies that you actually can short from a technical perspective. A lot of the intersection right now is SPACs."

7. "You had all of these SPAC IPOs last year because of a flood of unsophisticated retail that came into the market. That is just a very cynical, predatory play on unsophisticated retail. That's not to say every single one of these things is intellectually fraudulent and is going to be a bagel in the not-too-distant future, but I think a lot of them are."

8. "Things are fragile. When they do break, they're going to break hard, and not having real short exposure in the market is going to hurt the allocators who previously would have had that."

9. "Short-sellers get analogized to so many bad things, even bacteria. Here's the thing, your gut has a lot of bacteria in it that is necessary to help you digest. If you were to lose that bacteria, it probably is a bad sign, means you have ass cancer or something. If the market is losing the bacteria of short sellers, that's probably a sign that things are not healthy, and that the market is not fulfilling the function for which it exists."

10. "One of the upshots of all the retail participation is that there's a lot more liquidity in the options market. Retail investors have made it a lot more dangerous on the short side, but have also created the opportunity to put on meaningful, put-option trades that weren't there before because the liquidity in the options markets just didn't exist. So there is that positive flip side of the coin for shorts."